iio: ltr501: Add regmap support.

Added regmap support. It will be useful to handle
bitwise updates to als & ps control registers.
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/light/ltr501.c

@@ -16,6 +16,7 @@
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/delay.h>
+#include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -33,6 +34,7 @@
 #define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
 #define LTR501_ALS_PS_STATUS 0x8c
 #define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
+#define LTR501_MAX_REG 0x9f
 
 #define LTR501_ALS_CONTR_SW_RESET BIT(2)
 #define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))
@@ -45,23 +47,25 @@
 
 #define LTR501_PS_DATA_MASK 0x7ff
 
+#define LTR501_REGMAP_NAME "ltr501_regmap"
+
 struct ltr501_data {
 	struct i2c_client *client;
 	struct mutex lock_als, lock_ps;
 	u8 als_contr, ps_contr;
+	struct regmap *regmap;
 };
 
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 {
 	int tries = 100;
-	int ret;
+	int ret, status;
 
 	while (tries--) {
-		ret = i2c_smbus_read_byte_data(data->client,
-					       LTR501_ALS_PS_STATUS);
+		ret = regmap_read(data->regmap, LTR501_ALS_PS_STATUS, &status);
 		if (ret < 0)
 			return ret;
-		if ((ret & drdy_mask) == drdy_mask)
+		if ((status & drdy_mask) == drdy_mask)
 			return 0;
 		msleep(25);
 	}
@@ -72,21 +76,30 @@ static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 
 static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
 {
-	int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
+	int ret;
+
+	ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
 	if (ret < 0)
 		return ret;
 	/* always read both ALS channels in given order */
-	return i2c_smbus_read_i2c_block_data(data->client,
-					     LTR501_ALS_DATA1,
-					     2 * sizeof(__le16), (u8 *)buf);
+	return regmap_bulk_read(data->regmap, LTR501_ALS_DATA1,
+				buf, 2 * sizeof(__le16));
 }
 
 static int ltr501_read_ps(struct ltr501_data *data)
 {
-	int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
+	int ret, status;
+
+	ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, LTR501_PS_DATA,
+			       &status, 2);
 	if (ret < 0)
 		return ret;
-	return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
+
+	return status;
 }
 
 #define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
@@ -170,11 +183,10 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
 				*val = 0;
 				*val2 = 5000;
 				return IIO_VAL_INT_PLUS_MICRO;
-			} else {
+			}
 			*val = 1;
 			*val2 = 0;
 			return IIO_VAL_INT;
-			}
 		case IIO_PROXIMITY:
 			i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
 				LTR501_CONTR_PS_GAIN_SHIFT;
@@ -219,8 +231,8 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 				data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
 			else
 				return -EINVAL;
-			return i2c_smbus_write_byte_data(data->client,
-							 LTR501_ALS_CONTR,
+
+			return regmap_write(data->regmap, LTR501_ALS_CONTR,
 					    data->als_contr);
 		case IIO_PROXIMITY:
 			i = ltr501_get_ps_gain_index(val, val2);
@@ -228,8 +240,8 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 				return -EINVAL;
 			data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
 			data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
-			return i2c_smbus_write_byte_data(data->client,
-							 LTR501_PS_CONTR,
+
+			return regmap_write(data->regmap, LTR501_PS_CONTR,
 					    data->ps_contr);
 		default:
 			return -EINVAL;
@@ -258,13 +270,15 @@ static const struct iio_info ltr501_info = {
 	.driver_module = THIS_MODULE,
 };
 
-static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
+static int ltr501_write_contr(struct ltr501_data *data, u8 als_val, u8 ps_val)
 {
-	int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
+	int ret;
+
+	ret = regmap_write(data->regmap, LTR501_ALS_CONTR, als_val);
 	if (ret < 0)
 		return ret;
 
-	return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);
+	return regmap_write(data->regmap, LTR501_PS_CONTR, ps_val);
 }
 
 static irqreturn_t ltr501_trigger_handler(int irq, void *p)
@@ -276,7 +290,7 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 	__le16 als_buf[2];
 	u8 mask = 0;
 	int j = 0;
-	int ret;
+	int ret, psdata;
 
 	memset(buf, 0, sizeof(buf));
 
@@ -292,10 +306,8 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 		goto done;
 
 	if (mask & LTR501_STATUS_ALS_RDY) {
-		ret = i2c_smbus_read_i2c_block_data(data->client,
-						    LTR501_ALS_DATA1,
-						    sizeof(als_buf),
-						    (u8 *)als_buf);
+		ret = regmap_bulk_read(data->regmap, LTR501_ALS_DATA1,
+				       (u8 *)als_buf, sizeof(als_buf));
 		if (ret < 0)
 			return ret;
 		if (test_bit(0, indio_dev->active_scan_mask))
@@ -305,10 +317,11 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 	}
 
 	if (mask & LTR501_STATUS_PS_RDY) {
-		ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
+		ret = regmap_bulk_read(data->regmap, LTR501_PS_DATA,
+				       &psdata, 2);
 		if (ret < 0)
 			goto done;
-		buf[j++] = ret & LTR501_PS_DATA_MASK;
+		buf[j++] = psdata & LTR501_PS_DATA_MASK;
 	}
 
 	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());
@@ -321,26 +334,48 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 
 static int ltr501_init(struct ltr501_data *data)
 {
-	int ret;
+	int ret, status;
 
-	ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
+	ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);
 	if (ret < 0)
 		return ret;
-	data->als_contr = ret | LTR501_CONTR_ACTIVE;
 
-	ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
+	data->als_contr = status | LTR501_CONTR_ACTIVE;
+
+	ret = regmap_read(data->regmap, LTR501_PS_CONTR, &status);
 	if (ret < 0)
 		return ret;
-	data->ps_contr = ret | LTR501_CONTR_ACTIVE;
 
-	return ltr501_write_contr(data->client, data->als_contr,
-				  data->ps_contr);
+	data->ps_contr = status | LTR501_CONTR_ACTIVE;
+
+	return ltr501_write_contr(data, data->als_contr, data->ps_contr);
 }
 
+static bool ltr501_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LTR501_ALS_DATA1:
+	case LTR501_ALS_DATA0:
+	case LTR501_ALS_PS_STATUS:
+	case LTR501_PS_DATA:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static struct regmap_config ltr501_regmap_config = {
+	.name =  LTR501_REGMAP_NAME,
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = LTR501_MAX_REG,
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_reg = ltr501_is_volatile_reg,
+};
+
 static int ltr501_powerdown(struct ltr501_data *data)
 {
-	return ltr501_write_contr(data->client,
-				  data->als_contr & ~LTR501_CONTR_ACTIVE,
+	return ltr501_write_contr(data, data->als_contr & ~LTR501_CONTR_ACTIVE,
 				  data->ps_contr & ~LTR501_CONTR_ACTIVE);
 }
 
@@ -349,22 +384,30 @@ static int ltr501_probe(struct i2c_client *client,
 {
 	struct ltr501_data *data;
 	struct iio_dev *indio_dev;
-	int ret;
+	struct regmap *regmap;
+	int ret, partid;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev)
 		return -ENOMEM;
 
+	regmap = devm_regmap_init_i2c(client, &ltr501_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Regmap initialization failed.\n");
+		return PTR_ERR(regmap);
+	}
+
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
+	data->regmap = regmap;
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);
 
-	ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
+	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
 	if (ret < 0)
 		return ret;
-	if ((ret >> 4) != 0x8)
+	if ((partid >> 4) != 0x8)
 		return -ENODEV;
 
 	indio_dev->dev.parent = &client->dev;
@@ -420,7 +463,7 @@ static int ltr501_resume(struct device *dev)
 	struct ltr501_data *data = iio_priv(i2c_get_clientdata(
 					    to_i2c_client(dev)));
 
-	return ltr501_write_contr(data->client, data->als_contr,
+	return ltr501_write_contr(data, data->als_contr,
 		data->ps_contr);
 }
 #endif